Sophia University

About: Sophia University is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Nonlinear system & Catalysis. The organization has 4986 authors who have published 7657 publications receiving 106567 citations. The organization is also known as: Jōchi Daigaku.

Density of states scaling at the semimetal to metal transition in three dimensional topological insulators.

Abstract: The quantum phase transition between the three dimensional Dirac semimetal and the diffusive metal can be induced by increasing disorder. Taking the system of a disordered Z2 topological insulator as an important example, we compute the single particle density of states by the kernel polynomial method. We focus on three regions: the Dirac semimetal at the phase boundary between two topologically distinct phases, the tricritical point of the two topological insulator phases and the diffusive metal, and the diffusive metal lying at strong disorder. The density of states obeys a novel single parameter scaling, collapsing onto two branches of a universal scaling function, which correspond to the Dirac semimetal and the diffusive metal. The diverging length scale critical exponent ν and the dynamical critical exponent z are estimated, and found to differ significantly from those for the conventional Anderson transition. Critical behavior of experimentally observable quantities near and at the tricritical point is also discussed.

The structure of metallo-DNA with consecutive thymine-HgII-thymine base pairs explains positive entropy for the metallo base pair formation.

Abstract: We have determined the three-dimensional (3D) structure of DNA duplex that includes tandem Hg(II)-mediated T-T base pairs (thymine-Hg(II)-thymine, T-Hg(II)-T) with NMR spectroscopy in solution. This is the first 3D structure of metallo-DNA (covalently metallated DNA) composed exclusively of 'NATURAL' bases. The T-Hg(II)-T base pairs whose chemical structure was determined with the (15)N NMR spectroscopy were well accommodated in a B-form double helix, mimicking normal Watson-Crick base pairs. The Hg atoms aligned along DNA helical axis were shielded from the bulk water. The complete dehydration of Hg atoms inside DNA explained the positive reaction entropy (ΔS) for the T-Hg(II)-T base pair formation. The positive ΔS value arises owing to the Hg(II) dehydration, which was approved with the 3D structure. The 3D structure explained extraordinary affinity of thymine towards Hg(II) and revealed arrangement of T-Hg(II)-T base pairs in metallo-DNA.

Global smoothing of Calabi-Yau threefolds.

Abstract: Yoshinori Namikawa I,*, J.H.M. Steenbrink 2 I Department of Mathematics, Sophia University, Kioi-Cho, Tokyo 102, Japan 2 Mathematical Institute, University of Nijmegen, Toernooiveld, 6525 ED Nijmegen, The Netherlands Oblatum 10-X-1994 & 13-VI-1995 Introduction Friedman [Fr] has studied the relationship between local and global deforma- tions of a threefold Z with isolated hypersurface singularities which admits small resolutions. One of his main results is as follows. Let Z be a Moishezon threefold with only ordinary double points { Pl ..... p. }. Assume that the canon- ical line bundle